Electric clock.



r; HOLDEN. ELECTRIC CLOCK.

APPLICATION FILED NOV. 30, 1912- Patented Sept. 22, 1914.

fzvyzwraa THANK HOLDEN,

His Ara-nann FRANK HOLDEN, OF LONDON, ENGLAND, ASSIGNOE T0 GENERALELECTRIC (Jtzlh'iPAltf'il,

' A CORPORATION or new YORK.

morale CLOCK.

Specification otLcttcrs Patent.

Tetented sea-puss,

A lication filed Noveniber so, 1912. Serial x0. 734,293.

To all whom it may concern Be it knowri tluit I, FRANK HOLDEN, a citizenof the United States, residing ct London, England, have invented certainnew and useful Improvements in Electric Clocks, of which the followingis a specifi cation.

This invention relates to electric clocks,

which normally acts to vary the time of the. pendulummr balance wheel inthis type of clock.

In; this end the invention consists in the employment of an auxiliarydriving device, such as a small motor for operating the mechanism, thecircu-it of the motor being supplied with-current from a battery orother-convenient source and controlled by a contact cal-cried by thependulum.

In the accompanying drawing, Figure l I illustrates diagrammatically oneform of the invention, Fig. 2 is a-dingrammatic view 01% certain of theelectrical connections, a'nd Fig. 3 illustrates a modified detail ofconstruction.

Referring to the figures of the drawing, there is shown a pendulum 1which is similar to that described in British Patent, No. 14,873 of1909. The'pendulum carries a coil 2 adapted to swing in the magneticfield of the permanent magnets-16 and periodically energized to producean impulse by means of n pivoted contact 3. The contact 3 is alsocarried by the pendulum and is adapted to engage the fixed contacts 4,thus completing an electric circuit. Fig. 2 of the drawings illustratesdiagrammatically the electrical connections of the circuit.

Instead of utilizing the movement of the pendulum for operating directlythe indi' eating or clock mechanism, I provide an ellicient electricmotor having small internal losses, such as is used in some types ofelectric' meters. This motor is connected in any suitable manner, as forexample, by means of a. chain or cord 6, to a wheel -provided with oneor more radially projecting pins or contacts 8, preferabl of some gootlconducting muterial, such as silver.

The wheel 7 is rotatably mounted in a position that the in or pins-8project thepath of a flexib e contact carried by -ie pendulum. The motoris supplied with current from a convenient source, such as a battery i0,wlnchmafbe the same as that supplylng the current-for actuating thependulum, or may be a separate battery. G'ne terminal of this battery isconnectedto the pendulum, while the "otheris connected through the motorarmature to the cloen mechanism or-contaot wheel in such a man-5 menthat the circuit is completed when one of the pins 8 on the wheel isengaged by the flemble contact 9 on the pendulum.

contact wheel is connected to the indicating or clock mechanism, WlllCllcomprises. the

gearing 11 and the indicating hands '12, mthat the motor when suppliedwith current drives said mechanism throughthc contact wheel.

The operation is as follows: When pendulum is swinging in-onedirection,for example from left to right in the drawing. the flexible contact 9cnrried therchy engages one of the .pins 8 on the contact wheel. Thiscompletes the circuit of the n'iotoriwhich immediately accelerates,driving the contest wheel and the clock mechanism through the chain orcord 6. On the return stroke the flexible contact does not engage acontact on the wheel 7, as these contacts are preferably so arranged asnot to come into the path the flexible contact on the return stroke. Ifnot so arranged,however, the flexible contact may he hinged, as shown ati l in 3,

so as to ride freely over the wheel contacts on the return stroke, inwhich case the been of the flexible contact or the portion of the Wheelcontact-s engaged thereby may be in sulnt'ed as at 15, so that the motorcircuit will not be completed.

The moiment'm inertia o'f'the motor is such that when once started itwill. run for a considerable time at a practically constant speed andduring this time its circuit may or may not be completed throu h the moving contacts. of the motor are such that, without t a operzition of thependulum, it runs t a r per cent. slow, or as nearly as practice" theThe electrical characteristics.

always less than, the sp ed required to make the clock give the righttime. Thus, granted e starting condition under which the pendu-.

him and. r'evolvingcontacts synchronize, it is evident llli l't therevolving contacts cannot gain appreciably on the pendulum contact, asthecjontacts no longer.,.close the motor circult, and the motor losesthe accelerating effectofthehpplied"voltage. It is a matter ofproporti-oiiin'g -"tl'ie electrical characteristics of the m'otor'tarrange that the closing of thepontzicts produces enough acceleration sothat the revolving contacts. cannot fall hehindthe pendulum contactmThus before an appreciable; decrease-1n speed of the revolv- @11contests takes place a Contact on the contactmvhel; engages the pendulumcontact to complete the Inotor-circuitnnd accelerate the motor.These'accelerating impulses will occur at substantially regularintervals so that the number of revolutions made by the con-'Withazdrivingmechanism, such as above described, the" movement of thehands, the secondhand more particularly, is continuous and not periodicas is the case with the usual pendulum driven clocks.

It will he obvious that various modificm tions' of the arrangementdescribed above, may be made without departing from the spirit and scopeof this invention.

What I claim as new and desire to secure by Letters Patent of'the UnitedStates, is:

.1. Amelectric clock comprising an elec tricniotor having a continuouslyrotatable member, an electric circuit operatively rea, meansfor-synchronizing the motor.

opcratively related to said motor, a movable 1 contact included in saidcircuit and adapted to be actuated by said motor, a second I110?- ablecontact included in said circuit and 00 operating with said firstmentioned movable contact, and zipcnduluzn adapted to actuate saidsecoi'u'l movable Contact.

An cl ric clock comprising an inclicaling mechanism, an electric motoroperm Lively connected to said mechanism, an electric circuit inoperative relation to said motor, and a penduluin'zidapted to completesaid circuit when thespeed of the motor de creases a predeterminedamount.

l. electric crock comprising an indicating mechanism, an electricmotor'having a continuously rotatable member for driving said mechanism,an electric circuit operatively related to said motor, 3nd :1 pendw lumadapted to control said circuit An electric clock comprising, anindicating mechanism, an electric. motor for driving said mechanism, anelectric circuit in operative relation'to said motor, a con tact wheelin said circuit and dri venby said motor snd a pendulum having a Contactincluded insziid electric circuit-and adapted to engage saidcontact'wheel whenthe speed of the motor decreases predetermined amount.

In witness whereof, I have, hereunto set my hand this liith day ofNovember, 1912,

7 FRANK HOLDE-N.

lVitnesses':

FREDK. J. SKOYLEs,

c Gimmes H. Bnnosss.

